Glycopeptide antibiotics can be classified in four groups based on their chemical structure (according to Yao, R. C. and Crandall, L. W., Glycopeptides, Classification, Occurrence, and Discovery in Glycopeptide antibiotics, ed. Nagarajan, R., Marcel Dekker, Inc., N.Y, N.Y., Chapter 1, pp. 1-27 (1994)):                Group I (or the vancomycin type) has aliphatic amino acids at positions 1 and 3;        Group II (or the avoparcin type) has aromatic amino acid residues at positions 1 and 3;        Group III (or the ristocetin type) is similar to group II but for an ether linkage joining the aromatic amino acids at positions 1 and 3; and        Group IV (or the Teicoplanin type) has the same amino acid arrangement as group III plus a fatty acid residue attached to the amino sugar.        
Examples on glycopeptide antibiotics are listed in U.S. Pat. No. 4,845,194 A, and in EP 836 619 B1, wherein the term dalbaheptide is used for glycopeptide antibiotics. The glycopeptides can be manufactured as disclosed in the art, such as by fermentation.
Teicoplanin is a glycopeptide antibiotic produced by Actinoplanes teichomyceticus and was discovered during a scientific research program aiming to find new molecules of microbial origin that inhibited bacterial cell wall synthesis. (Goldstein, B. et al, Teicoplanin in Glycopeptide Antibiotics, ed. Nagarajan, R., Marcel Dekker, Inc., N.Y, N.Y., Chapter 8, pp. 273-307 (1994)). It was first described in 1978 and ten years later it was introduced into clinical practice in Italy. (Parenti, F. et al, J. Chemotherapy, Vol. 12, pp. 5-14, (2000)).
Numerous methods for purifying glycopeptide antibiotics have been disclosed. According to the method disclosed in EP 479 086 B1, in order to increase extraction efficiency of teicoplanin A2, the fermentation broth is adjusted to a pH between 10 and 11.5, prior to filtration. The filtrate of the fermentation broth is loaded on a polyamide resin and teicoplanin is precipitated from the eluate with an excessive amount of acetone and left to stand for 3 hours. The supernatant is decanted and the rest is filtered. The resulting cake is washed with acetone to recover teicoplanin A2. This method has the problem of solvent accumulation, since it uses an excessive amount of acetone in diverse steps.
U.S. Pat. No. 4,845,194 discloses a method for recovering vancomycin-type glycopeptide antibiotics (e.g. teicoplanin and vancomycin), in which a cation exchange resin having a cross-linkage of 2% or less is added to the fermentation broth to adsorb teicoplanin to the resin and a 100 mesh sieve is used to separate the mycelia from the resin. Then, the resin is washed with purified water, followed by elution to recover teicoplanin.
Korean Patent Publication No. 2000-0066479 discloses a method for producing teicoplanin A2, in which a fermentation broth is adjusted to pH 11 and centrifuged, and the supernatant is adsorbed onto a synthetic adsorbent resin such as XAD-16, HP-20 and activated carbon or silica gel, eluted with a 50 to 80% methanol solution and recovered under reduced pressure to obtain teicoplanin as crude powder. The crude teicoplanin is dissolved in a solution of sodium acetate and purified by sugar affinity chromatography.
US patent application 20040024177 A1 discloses method for purifying teicoplanin A2 comprising: (i) a primary pre-purification step of purifying a filtrate of fermentation broth of a strain using a synthetic adsorbent; (ii) a secondary pre-purification step of purifying the primary pre-purification solution using a cation exchange resin having a high cross-linkage, a catalytic resin or a chelate resin; (iii) a final purification step of purifying the secondary pre-purification solution using a reversed phase resin; and (iv) a powder-forming step.